In Pennsylvania, the statute of limitations on debt is four years. That means that if a debt has a period of no debtor activity for four years the debt is no longer collectible in the Commonwealth.
So does this mean my creditor can no longer harm me once four years has past? Like most things in law, the answer is not exactly.
Let’s start with what the creditor cannot do. The creditor can no longer successfully sue you for a judgment nor can they file a valid proof of claim for debt you owe them in a Chapter 13 bankruptcy case. A debt this old is also called “time barred. ”
Now we get to what the creditor can do. 
A creditor can still send you a collection letter requesting payment. You can send a letter asking for anything. I could send you a letter asking for a pink hippo. Just because I ask for it in the letter doesn’t mean you have to comply. Even so, there is nothing overtly illegal in requesting you pay a debt, even if they no longer can sue you for the balance.
A creditor can also attempt to collect the debt using phone calls. The Fair Debt Collection Practices Act (FDCPA) allows collectors to make contact once per day.
There is nothing barring the collector from attempting to collect a time-barred debt over the phone, however if they threaten to sue you they are violating the FDCPA because it is a thread to do something they aren’t able to do legally. This could be classified as an idle threat at best. 
If you allow them, a debt collector will drive you nuts trying to collect an invalid debt, and if you make a payment to them to get them off your phone, you may inadvertently start the statute of limitations all over again.
You don’t have to put up with a debt collector’s constant phone calls!
Rather than give in to one of these snakes in the grass, ask them for a mailing address and send them a letter telling them to stop calling. Its called a cease communication letter. Send it certified, then if they call again they have violated the FDCPA. Instead of collecting from you, they may wind up receiving a heavy penalty instead.
If its been more than four years since you paid a debt or you used a credit card and a debt collector comes calling, don’t give them a thing, just send a cease communication letter and remind them that they are SOL. Their debt is beyond the statute of limitations and they can’t touch you.
